Birth factors influence infant gut microbiome, and subsequent risk of obesity & allergies

SyMBIOTA research published in the journal Gastroenterology explores how cesarean delivery and other birth events infuence a baby’s gut microbiome at three and 12 months of age, and how this can increase the risk of allergies and obesity later in childhood.

The research used data from 1,667 mothers and infants participating in the CHILD Cohort Study. The researchers analyzed the gut microbes in infant stool samples, and cross-referenced this analysis with body-mass index (BMI) measurements and the results of allergy tests that these same children underwent at ages one and three years.

The study found that infants born by cesarean section were more likely to have a high BMI score at one and three years of age. The researchers also found that at three months these babies had an altered ratio of two bacteria – Enterobacteriaceae and Bacteroidaceae – and that this change represented the dominant path to overweight. At 12 months of age the same infants had a higher Enterobacteriaceae/Bacteroidaceae (E/B) ratio and colonization with the bacterium Clostridioides difficile (C. difficile), which the researchers identified as the main pathways leading to allergic sensitization.

Infants born after prolonged labour associated with a first pregnancy were also found to be at a higher risk for these health outcomes, with the E/B abundance ratio again being the most important microbiota mediator to overweight and allergic sensitization, and with Bifidobacterium also playing a role in overweight development.